If YellowBlueBird has a small engine on it, that amount of wt would be expected. Most of the sticks that I have flown have a G26 on them, which makes up for the wt. What engine are you using? Good catch on the balance of the prop, wasn't awake yet, and having first cup of coffee. The diver bb epoxy slurry I've used on scale planes/jets to help hide the wt. Great for tight spaces. Also for balancing laterally with block balsa wing tips. Drill into the balsa, put the slurry in, and patch with putty, epoxy and micro balloons, etc Put too much in or some flights down the road, you can still add or take the wt out with a Dremel.